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Communication
(a) Communication between personnel involved in the lift operation shall be maintained continuously during
all jack movement. If at any time communication is disrupted, the jack operator(s) shall stop all movements
until communication is restored.
(b) Signals to the jack operator should be in accordance with the ASME B30.1. If special signals are required,
they shall be agreed upon by the load-handling personnel prior to jacking operations. Signals shall be
discernible or audible at all times. No action shall be taken unless signals are clearly under-stood.
(c) Jack operators shall obey any stop signal.
Synchronized Lifts
(a) When using jacks to lift the entire load in a synchronized lift, uneven raising and lowering can cause
cross loading, instability, and overloading.
(b) Some loads may require multiple lifting points and complex lifting procedures. A qualified person shall
analyze the operation and instruct all personnel involved in the proper selection and positioning of the jacks
and the movements to be made.
(c) When using multiple ratchet jacks simultaneously, ensure they are identical type (manufacturer, make,
model, and capacity), or lifting rate to ensure they are evenly loaded during jacking.
(d) Unsynchronized lowering can cause an overload to a jack and may result in kickback of tl1e jack handle
or instability of the load.
Blocking
(a) While jacking, blocking should follow the load up or down to serve as an arresting device if the load falls.
(b) Wedges or shims should be used as necessary to ensure the load is completely supported at its blocking
points.
(c) Blocking shall be of sufficient thickness, width, and length to prevent shifting, toppling, or excessive
settlement of the load.
(d) Blocking shall be of sufficient strength to prevent crushing, bending failure or shear failure, and to
adequately transmit the load's weight to the supporting surface.
Horizontal Jacking
(a) Applications may arise where jacks are used in a position other than vertical. These applications, referred
to as horizontal jacking, require special attention.
(b) Horizontal jacking shall comply with the requirements of, Operating Practices, as applicable
(c) A plan shall be developed and communicated to affected personnel before horizontal jacking operations
begin. The plan shall consider but not be limited to the following:
1. Load weight
2. Effects of friction
3. Angle from horizontal plane
4. Load stability and control
5. Obstructions
6. Jack base support
7. Jack support
8. Load contact point
9. Handle clearance
10. Center of gravity of the load
11. Personnel safety
(d) When jacking horizontally, the base of the jack should be perpendicular to the direction of load
movement.
(e) If multiple jacks are used, maintain parallel lines of force to prevent side loading of the jacks.